With minicamps wrapping up offseason programs this week, Gregg Rosenthal takes a look at the biggest remaining weak spot for each AFC team heading toward the 2018 season.

Baltimore Ravens: Joe Flacco

The invaluable Chase Stuart at Pro Football Reference wrote a piece this week noting that Flacco has played longer for one team than any below-average quarterback, according to adjusted net yards per attempt. I'd argue that Flacco wasn't below average until the last three seasons, but three seasons is a long time in the NFL. The presence of first-round pick Lamar Jackson puts the veteran on a short leash. With a new cast of receivers and a rare healthy offseason, Flacco might need to get out of the gates quickly to keep his job.

Buffalo Bills: Passing game

The easy answer here is to list quarterback, where AJ McCarron, Nathan Peterman and Josh Allen have combined to make five NFL starts. But it will be unfair to pin all of Buffalo's expected struggles on the quarterbacks if they aren't protected and can't find open receivers. The Bills' offensive line lost three quality starters and the wideout group ranks among the league's worst. This would be an uphill battle for even the most gifted quarterback.

Cincinnati Bengals: Inspiration

The Dalton Scale, created by the immortal Chris Wesseling, was built to determine who is a true franchise quarterback, with Andy Dalton acting as the league's prime meridian. If a quarterback falls below Dalton, his team should be looking for a new one. The Bengals are entering their eighth season with Dalton, and Cincinnati's roster is starting to resemble its quarterback, like owner and dog. The Bengals' secondary, pass rush and offense land comfortably around average. We could start to evaluate coaches using the Marvin Lewis Scale. After 15 years with Lewis at the reins, what can jolt this team out of the NFL's soft middle?

Cleveland Browns: Offensive tackle

Hue Jackson has underachieved for two straight seasons. He is out of excuses with this roster, which could reasonably be called average or better at nearly every position ... except tackle. The retirement of Joe Thomas hurts extra because of the options to replace him. Shon Coleman and second-round rookie Austin Corbett will battle on the left side, while former Steelers backup Chris Hubbard was signed to play right tackle. If Tyrod Taylor and/or Baker Mayfield get decent protection, this offense should be a lot of fun to watch.

Denver Broncos: Offensive line

At least John Elway tried to fix his long-running sinkhole. Last year's prized free-agent pickup, Ronald Leary, is moving back to his natural left side. Denver imported Cardinals veteran Jared Veldheer to slow the revolving door at right tackle. The team is hopeful for a second-year leap from 2017 first-round left tackle Garett Bolles. The Broncos' line, however, has become a group expected to struggle until it proves otherwise, much like the Broncos' line was once expected to blow open holes for little-known running backs.

Houston Texans: The Football Gods

I could ramble on about the dangers of trusting Deshaun Watson's blind side to Julie'n Davenport, but the shaky Houston offensive line serves my larger point. The Texans need luck. They need Watson's recovery from a torn ACL to go smoothly. They need J.J. Watt to be healthy enough to be J.J. Watt again. They need Jadeveon Clowney and Watt to be healthy together at the same time. This is perhaps the most top-heavy team in football, one with almost limitless potential if the injury luck finally goes its way this season.

Indianapolis Colts: The entire defense

I don't see it. I look at Indianapolis' defensive roster and don't see a path to a top-20 performance from that side of the ball. The Coltsfinished No. 27 in defensive DVOA last year and will have to manufacture pressure to help protect an inexperienced secondary. General manager Chris Ballard clearly has a vision of how this can work, but even a healthy Andrew Luck figures to have a tough time overcoming this group.

Jacksonville Jaguars: Blake Bortles

The rest of the team is ready to win a championship. The league's best defense has a chance to improve because of all its young, improving players like Myles Jack, Jalen Ramsey and Yannick Ngakoue. The offensive line is in the best shape it's been in during general manager Dave Caldwell's tenure. The pass catchers are plentiful. It's now on Bortles to reward all the faith his organization has placed in him, one that has been remarkably understanding of the many weeks in which he hurts the team's chances to win.

Kansas City Chiefs: Secondary

The return of Eric Berry can't solve everything. At least two of the team's outside cornerback spots (Steven Nelson, David Amerson) are cause for concern, as is the other safety position opposite Berry. The Chiefs were smartly aggressive overhauling their defense after getting run over by the Titans in the playoffs, but this is still a team that figures to get caught in too many shootouts.

It had to drive Chargers coach Anthony Lynn crazy that his team was playoff-worthy a year ago if not for its struggles in the running game on both sides of the ball. The team used its first four draft picks on defense in an effort to get tougher, and better health at linebacker will go a long way. The Bolts have enough talent in Melvin Gordon and the current offensive linemen to improve from within. Just upgrading to average in the running game on both sides of the ball should make Los Angeles a playoff team.

Miami Dolphins: Defensive tackle

With Ndamukong Suh in Los Angeles, the Dolphins' starters at DT are Jordan Phillips and Davon Godchaux, two young players with more potential than production thus far. Their development is especially crucial because they are playing in front of a linebacker group of Kiko Alonso and two guys who have yet to take an NFL snap (Raekwon McMillan and Jerome Baker). Opposing teams figure to test the Dolphins up the middle until they prove they can hold up.

New York Jets: Pass rush

It's only been a few years since the Jets had one of the best defensive-line trios in football with Sheldon Richardson, Muhammad Wilkerson and Leonard Williams. Only Big Cat remains, but it's worth remembering that even the 2015 Jets didn't generate pressure coming off the edge. That formula worked well enough for coach Todd Bowles back then, but it's hard to overcome a dearth of pure pass rushers.

Oakland Raiders: Secondary

It's a bad sign when a relatively quiet first-round pick from two years ago, Karl Joseph, is the surest thing in the entire defensive backfield. Oakland is counting on a journeyman (Rashaan Melvin) to be the team's No. 1 cornerback and a raft of players coming off injuries or disappointing years to play major roles, including Gareon Conley, Reggie Nelson, Leon Hall and Shareece Wright. You can almost hear the sarcastic Jon Gruden press conference quotes from here.

Pittsburgh Steelers: Inside linebacker

In 2018, defenses can generally manage a weakness at inside linebacker. It's just disarming to see the Steelers, of all teams, have trouble at the position. The current tag-team combination of Vince Williams and journeyman Jon Bostic are expected to start in Pittsburgh's "base" sets, but no one expects them to fill the shoes of Ryan Shazier. It's easy to imagine Tom Brady targeting either of these linebackers, allowing some Patriots running back to sprint away and score a backbreaking touchdown on third down.

Tennessee Titans: Nothing

This team is perfect. Kudos to general manager Jon Robinson. Super Bowl, baby!